JP2009029044A - Image forming apparatus, image forming method, and image forming program - Google Patents

Abstract

An image forming apparatus, an image forming method, and an image forming program capable of improving the EMI countermeasure effect with a simple configuration.
Print data used for printing information when printing information on a recording medium and an output reference clock serving as a reference for outputting the print data are input to the head module, and the head module receives the print data and output reference. An image forming apparatus that prints information on a recording medium based on a clock includes an engine control unit 100 that inputs print information relating to the output timing of print data and clock information relating to an output reference clock to the head module as output timing information, and includes an output timing. The information is information for outputting print data by sequentially switching a plurality of types of cycles so that the cycle of the output reference clock is not constant.
[Selection] Figure 3

Description

  The present invention relates to an image forming apparatus, an image forming method, and an image forming program for recording information on a recording medium by ejecting ink.

  In an image forming apparatus such as an ink jet printer, a great deal of development time and development cost are required for EMI (Electro Magnetic Interference) countermeasures, which has an impact when developing an ink jet printer. This EMI is radiated noise that is generated when the clock in the system device generates a single frequency and radiation at that frequency and its harmonics increases.

  As general EMI countermeasures, there are a method of inserting a ferrite core into a cable, a method of forming a multilayer substrate, a method of considering a PWB pattern routing method (layout), and the like. These measures against EMI require a long period of time, and increase the cost of the entire apparatus by inserting a ferrite core.

  In the image reading apparatus described in Patent Document 1, in order to lower the EMI radiation level, in the image processing process, the clock signal is not frequency-spread in the processing process by the first circuit block, but by the other second circuit block. In the process, the clock signal is frequency spread. Further, by providing a buffer memory between the first circuit block and the second circuit block, line synchronization is achieved and image data is transferred.

  In the electronic device described in Patent Document 2, the modulation width of the spread spectrum clock for each electronic device is switched and set according to the operation mode of each electronic device constituting the electronic device.

JP 2002-33858 A JP 2005-223770 A

  In the former and the latter conventional techniques, a circuit or mode considered to require EMI measures is selected, and frequency spreading is performed on the selected circuit or mode. For this reason, SSCG (Spread Spectrum Clock Generator) must be used for frequency spreading, and there is a problem in that the cost increases due to the mounting of SSCG.

  The present invention has been made in view of the above, and an object of the present invention is to obtain an image forming apparatus, an image forming method, and an image forming program that improve the EMI countermeasure effect with a simple configuration.

  In order to solve the above-described problems and achieve the object, the invention according to claim 1 is characterized in that when printing information on a recording medium, the print data used for printing the information and the reference of the timing for outputting the print data In the image forming apparatus in which the head module prints the information on the recording medium based on the print data and the output reference clock, the print information on the output timing of the print data and A head module control unit that inputs clock information related to the output reference clock as output timing information to the head module, and the output timing information sequentially switches a plurality of types of cycles so that the cycle of the output reference clock is not constant. To output the print data And wherein the door.

  According to a second aspect of the present invention, the image forming apparatus according to the first aspect further includes an input unit that externally inputs the print information and the clock information and sets the output timing information in the head module control unit. It is characterized by providing.

  According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the print information has a delay time from the output of the output reference clock to the output of the print data. It is characterized by.

  According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the head module control unit outputs output timing information having a different delay time for each of the head modules. It inputs to each said head module, It is characterized by the above-mentioned.

  According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects, the cycle of the output reference clock is set to be switched every time the print data is switched. It is characterized by being.

  According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the cycle of the output reference clock is switched based on a print position of information on the recording medium. It is set as follows.

  According to a seventh aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the head module control unit is configured to change a cycle variation range of the output reference clock and a preset range. The plurality of types of cycles are set based on a fluctuation ratio, and the output timing information using the set types of cycles is input to the head module.

  According to an eighth aspect of the present invention, in the image forming apparatus according to any one of the first to seventh aspects, the head module control unit outputs the print data so as to satisfy the AC characteristics of the head module. It is characterized by controlling the timing.

  According to a ninth aspect of the present invention, when printing information on a recording medium, print data used for printing the information and an output reference clock serving as a reference for outputting the print data are input to the head module, In the image forming method in which the head module prints the information on the recording medium based on the print data and the output reference clock, the head uses the information on the output timing of the print data and the information on the output reference clock as output timing information. A head module control step for inputting into the module, wherein the output timing information is information for switching the plurality of types of cycles in order so as to output the print data so that the cycle of the output reference clock is not constant. To do.

  The invention according to claim 10 is a program that causes a computer to execute the image forming method according to claim 9.

  According to the first aspect of the invention, since the print data is output by sequentially switching a plurality of types of cycles so that the cycle of the output reference clock is not constant, the output reference clock can be spread in frequency. Therefore, unnecessary noise due to the transfer reference clock and the data signal can be reduced, and the effect of EMI countermeasures can be improved with a simple configuration.

  According to the second aspect of the invention, since the print timing and the clock information are externally input and the output timing information is set, any output timing information can be easily set. Therefore, it is possible to output print data at an appropriate output timing according to the head module.

  According to the third aspect of the present invention, since there is a delay time from the output reference clock to the output of the print data, unnecessary noise for the data signal of the print data can be reduced. Therefore, it is possible to improve the EMI countermeasure effect with a simple configuration.

  According to the fourth aspect of the present invention, the delay time from the output of the output reference clock to the output of the print data is a delay time for each head module, so that the print data to each head module is unnecessary. Noise can be reduced. Therefore, even if there are a plurality of head modules, an effect of improving the EMI countermeasure effect with a simple configuration is achieved.

  According to the invention of claim 5, since the cycle of the output reference clock is set to be switched every time the print data is switched, the output reference clock can be easily spread in frequency. Therefore, it is possible to improve the EMI countermeasure effect with a simple configuration.

  According to the invention of claim 6, since the cycle of the output reference clock is set to be switched based on the printing position of the information on the recording medium, the output reference clock can be easily spread in frequency. . Therefore, it is possible to improve the EMI countermeasure effect with a simple configuration.

  According to the seventh aspect of the present invention, since a plurality of types of periods are set based on the preset fluctuation range and fluctuation ratio of the output reference clock, the period can be easily set and the output reference clock can be set. The clock can be frequency spread. Therefore, it is possible to improve the EMI countermeasure effect with a simple configuration.

  According to the eighth aspect of the invention, since the print data output timing is controlled so as to satisfy the AC characteristics of the head module, it is possible to output the print data so as to reliably satisfy the AC characteristics of the head module. Become. Therefore, it is possible to improve the EMI countermeasure effect with a simple configuration.

  According to the ninth aspect of the invention, since the print data is output by sequentially switching a plurality of types of cycles so that the cycle of the output reference clock is not constant, the output reference clock can be spread in frequency. Therefore, unnecessary noise due to the transfer reference clock and the data signal can be reduced, and the effect of EMI countermeasures can be improved with a simple configuration.

  According to the invention of claim 10, the image forming method described in claim 9 can be realized by using a computer by causing the computer to read and execute the same. There is an effect.

  Exemplary embodiments of an image forming apparatus, an image forming method, and an image forming program according to the present invention are explained in detail below with reference to the accompanying drawings.

(Embodiment)
In the image forming apparatus according to the present embodiment, the cycle of the transfer reference clock (output reference clock) serving as a reference for the output timing of the print data is changed to a desired cycle by software setting. Specifically, based on an externally input instruction, the cycle of the transfer reference clock is changed variously so that the cycle of the transfer reference clock is not constant. As a result, since the spectrum spread can be performed in a pseudo manner, the transfer reference clock can be frequency-spread to improve the EMI countermeasure effect.

  A configuration of an ink jet recording apparatus which is an example of an image forming apparatus will be described with reference to FIGS. 1 and 2. FIG. 1 is a plan view showing a schematic configuration of an inkjet recording apparatus according to an embodiment of the present invention, and FIG. 2 is a front view showing a schematic configuration of the inkjet recording apparatus according to the embodiment of the present invention.

  The ink jet recording apparatus 50 is an apparatus that forms information such as an image on the paper (recording medium) 11 by improving the EMI countermeasure effect by changing the frequency diffusion while considering the AC characteristics of the head module. The ink jet recording apparatus 50 includes a guide lot 1, a carriage 3, a main scanning motor 5, a driving pulley 6, a driven pulley 7, a timing belt 8, an encoder scale 10, a conveying belt 12, a conveying roller 13, and a tension roller 14. .

  The guide lot 1 holds the carriage 3 so that the carriage 3 moves in the main scanning direction. Specifically, the ink jet recording apparatus 50 holds the carriage 3 by a guide lot 1 that is horizontally mounted on left and right side plates (not shown).

  The carriage 3 is equipped with a recording head 4 composed of one to a plurality of liquid ejection heads. The recording head 4 includes, for example, a recording head 4y that discharges yellow (Y) ink (recording liquid) droplets, a recording head 4c that discharges cyan (C) ink droplets, and a recording head that discharges magenta (M) ink droplets. A recording head 4k for ejecting 4 m, black (K) ink droplets is mounted. Hereinafter, when the colors are not distinguished, they are referred to as “recording head 4”. Each of the recording heads 4y, 4c, 4m, and 4k is arranged so that nozzle surfaces (nozzle rows) on which a plurality of ink discharge ports (nozzles) are formed are aligned in a direction (sub-scanning direction) perpendicular to the main scanning direction. Each ink discharge port is mounted on the carriage 3 so that the direction of the ink discharge port is directed downward (paper 11 side).

  An encoder scale 10 having slits is provided along the main scanning direction on the rear surface (lower side) of the carriage 3. The carriage 3 is provided with an encoder sensor (not shown) that detects a slit of the encoder scale 10. In the ink jet recording apparatus 50, the encoder scale 10 and the encoder sensor constitute a linear encoder for detecting the position of the carriage 3 in the main scanning direction. The carriage 3 prints (records) a predetermined image on the paper 11 with ink droplets ejected from the recording heads 4y, 4c, 4m, and 4k.

  Although the case where the recording head 4 has an independent liquid ejection head for each color has been described here, the recording head 4 may have a liquid ejection head that ejects ink droplets of a plurality of colors. For example, one or a plurality of liquid ejection heads having a plurality of nozzle rows that eject ink droplets of each color may be used. The number of colors and the arrangement order are not limited to this, and any number of colors may be used, and any arrangement order may be used.

  The liquid discharge head of the recording head 4 uses various actuators as pressure generating means for generating pressure for discharging ink droplets. The pressure generating means includes, for example, a piezoelectric actuator such as a piezoelectric element, a thermal actuator that uses a phase change caused by film boiling of a liquid using an electrothermal transducer such as a heating resistor, and a shape memory alloy that uses a metal phase change caused by a temperature change. An actuator, an electrostatic actuator using electrostatic force, or the like is used.

  The main scanning motor 5 moves and scans the carriage 3 in the main scanning direction via a timing belt 8 passed between the driving pulley 6 and the driven pulley 7. The transport belt 12 is a transport unit that electrostatically attracts the paper 11 and transports the paper 11 at a position facing the recording head 4. The transport belt 12 is an endless belt having an annular shape, and is stretched between the transport roller 13 and the tension roller 14. The conveyor belt 12 circulates in the belt conveyance direction (sub-scanning direction) and is charged (charged) by the charging roller 15 while moving around. The conveyance roller 13 is a roller that rotates the conveyance belt 12. The tension roller 14 is a roller that applies a predetermined tension to the conveyor belt 12 and holds the conveyor belt 12 between the conveyor roller 13 and the tension roller 14.

  The conveyor belt 12 may be a single-layer belt or a belt composed of a plurality of layers. When the transport belt 12 is a transport belt having a single layer structure, the transport belt 12 contacts the paper 11 or the charging roller 15, so that the entire layer is formed of an insulating material. When the conveyor belt 12 is a multi-layer conveyor belt, an insulating layer is formed on the side where the conveyor belt 12 contacts the paper 11 and the charging roller 15, and the side where the conveyor belt 12 does not contact the paper 11 and the charging roller 15 is formed. The layer is preferably formed of a conductive layer.

  The ink jet recording apparatus 50 includes an engine control unit 100 described later as means for controlling the carriage 3 and the main scanning motor 5. Here, the configuration of the engine control unit 100 of the inkjet recording apparatus 50 will be described. FIG. 3 is a functional block diagram showing the configuration of the engine control unit.

  The engine control unit 100 includes a microcomputer (noted as CPU in FIG. 3) 101 composed of a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. Thus, the entire inkjet recording apparatus 50 is controlled.

  Image data transmitted from the host 200 is received by the host I / F unit 102 of the engine control unit 100 and converted into data suitable for the print mode by the image processing unit 103. The image data converted by the image processing unit 103 is stored in the image data storage unit 104.

  Based on an instruction from the CPU 101, the main scanning motor driving unit 106 rotates the main scanning motor 5 to move the carriage 3 in the forward and backward directions in the main scanning direction. A pulse signal is output from the encoder 18 mounted on the carriage 3 according to the moving distance of the carriage 3. The edge detection unit 107 detects an edge of the pulse signal output from the encoder 18 and sends the detected pulse signal to the main scanning speed detection unit 108, the main scanning position detection unit 109, and the recording head drive control unit 111.

  The main scanning speed detection unit 108 measures the output period of the pulse signal from the edge detection unit 107 and detects the speed of the carriage 3 (carriage speed) based on the measurement result. The main scanning speed detection unit 108 sends the detected carriage speed to the CPU 101.

  The main scanning position detection unit 109 counts the pulse signals from the edge detection unit 107 and detects the relative position (carriage position) of the carriage 3. The main scanning position detection unit 109 sends the detected carriage position information to the print area determination unit 110.

  The print area determination unit 110 determines whether the carriage position is within the print area based on the carriage position sent from the main scanning position detection unit 109. The print area determination unit 110 sends a determination result as to whether or not the carriage position is within the print area to the recording head drive control unit 111.

  The recording head drive waveform storage unit 105 stores drive waveform data for driving the recording head 4 (periods tp1, tP2, etc. described later). The recording head drive control unit 111 generates a driving waveform for driving the recording head 4 from the driving waveform data stored in the recording head driving waveform storage unit 105.

  When the carriage position is within the print area, the recording head drive control unit 111 drives the recording head 4 using the pulse signal from the edge detection unit 107 as a start timing, and discharges droplets from the recording head 4. At this time, the recording head drive control unit 111 drives the recording head 4 based on the image data stored in the image data storage unit 104 and the drive waveform data stored in the recording head drive waveform storage unit 105.

  In the present embodiment, not only when all the liquid application nozzles (the liquid application nozzle 2 described later) of the recording head 4 are driven simultaneously, the drive of each liquid application nozzle 2 is divided in time and driven. You may let them. Here, a case where the ink jet recording apparatus 50 is applied to an ink jet technique using a small current technique will be described. When all the liquid coating nozzles 2 are driven simultaneously, the recording quality is reduced due to the influence of crosstalk between the liquid coating nozzles 2, and a large current is temporarily required, so that the capacity of the power source is not increased. Profits may be generated. On the other hand, these disadvantages can be avoided by driving each liquid application nozzle 2 in a time-sharing manner.

  Hereinafter, a case where each liquid application nozzle 2 is driven in a time-sharing manner will be described. FIG. 4 is a block diagram showing the configuration of the logic circuit of the recording head. The logic circuit 60 includes a 192-bit shift register 61, a 192-bit latch 62, and a decoder 63. The shift register 61 sequentially outputs the image data IDATA input in synchronization with the data clock DCLK for each bit and inputs it to the latch 62. The latch 62 holds the bit signal input from the shift register 61 and outputs it from each of the 192 outputs during the period of the latch clock LTCLK. The decoder 63 converts the block selection signal (a 4-bit signal including four BENB0 to BENB3) into a signal designating each of the 12 blocks BE0 to BE11.

  The logic circuit 60 includes heaters H1 to H192, power transistors T1 to T192, and AND gates G1 to G192. The AND gates G1 to G192 take the logical product of the output from the decoder 63, the output from the latch 62, and the heat signal HEAT and output drive signals to the power transistors T1 to T192. The power transistors T1 to T192 drive the heaters H1 to H192. The heaters H <b> 1 to H <b> 192 constitute recording elements corresponding to the 192 liquid coating nozzles 2. In the ink jet recording apparatus 50, a logic circuit 60 is provided for each nozzle row (nozzle row 20 described later) in which the liquid coating nozzles 2 are arranged. The logic circuit 60 is disposed in the recording head 4, and the logic circuit 60 and the recording head 4 constitute a head module.

  FIG. 5 is a timing chart (1) in the case where one-pass printing is performed by time-division driving the nozzle row for each block by the logic circuit. LTCLK, DCLK, IDATA, BENB0-3, and HEAT in the figure indicate the latch clock LTCLK, data clock DCLK, image data IDATA, decoder input BENB0-3, and heat signal HEAT shown in FIG. 4, respectively.

  The 192-bit image data IDATA is temporarily taken into the shift register 61 in synchronization with the data clock DCLK. When the latch clock LTCLK is input to the shift register 61, it is transferred to the latch 62 and output to each of the 192-bit outputs of the latch 62. On the other hand, the block selection signals BENB0-3 are decoded into BE0-11 by the decoder 63, and ANDed by AND gates G1-G192 together with the output of the heat signal HEAT and the latch 62. The heaters H1 to H192 connected to the power transistors T1 to T192 to which drive signals are output from the AND gates G1 to G192 are energized, whereby ink is ejected from the liquid application nozzle 2 to the sheet 11. Recording is performed.

  For example, when the transfer frequency of the image data IDATA is 10 MHz, the time required to transfer the image data IDATA to all 192 liquid application nozzles 2 is about 20 μsec. On the other hand, the time required to drive the heaters H1 to H192 to obtain sufficient foaming power is 3 to 8 [mu] sec, and about 12 [mu] sec for all liquid coating nozzles 2 is about 100 [mu] sec. For this reason, compared with the time required for transferring the image data IDATA to all 192 liquid coating nozzles 2, the time for dividing and driving the liquid coating nozzle 2 in 12 is overwhelmingly longer.

  FIG. 6 is a dot arrangement diagram in a case where an image is recorded by driving the nozzle row for each block in a time-sharing manner. In FIG. 6, 48 liquid coating nozzles 2 are illustrated among the 192 total liquid coating nozzles 2, and the 49th and subsequent liquid coating nozzles 2 are not illustrated. Therefore, the logic circuit 60 is composed of 16 groups, each of which has 12 consecutive liquid application nozzles 2 as one group.

  In the logic circuit 60, 192 liquid application nozzles 2 are divided into predetermined blocks, and the heaters corresponding to the respective liquid application nozzles 2 are time-division driven in the order of the blocks. Specifically, first, the first liquid application nozzle of each group (16 of the first, 13th, 25th,..., 181st liquid application nozzles in all liquid application nozzles 2) 2 The block to be configured is the 0th block. Hereinafter, similarly, the second liquid coating nozzle of each group (16 of the second, 14th, 26th,..., 182th liquid coating nozzles in all liquid coating nozzles 2) 2 is configured. Is the first block. Each block has a twelfth liquid application nozzle (16 of the 12th, 24th, 36th,..., 192th liquid application nozzles in all liquid application nozzles 2) 2 Is the 11th block. Thereby, 192 liquid application nozzles 2 are divided into 12 blocks from 0th to 11th. In the logic circuit 60, each heater built in the liquid application nozzle 2 of the same block is connected to the same output of the decoder 63 via AND gates G1 to G192. The logic circuit 60 drives each heater in a time-sharing manner in the order of the 0th to 11th blocks shown in FIG.

  In such time-division driving, when an image is recorded on the paper 11 while moving the nozzle row 20 of the recording head 4 in a state perpendicular to the moving direction (main scanning direction), the vertical ruled lines are recorded with an inclination. End up. Therefore, as shown in FIG. 6, the nozzle row 20 of the liquid application nozzle 2 is attached in advance at a predetermined angle with respect to the main scanning direction so that the vertical ruled lines are orthogonal to the main scanning direction. Thereby, the inclination of the vertical ruled line can be corrected. As a result, when all the liquid application nozzles 2 have completed ejection, separate columns are recorded for each group.

  Next, the case where the inkjet recording apparatus 50 performs multi-pass recording in which the same area of the paper 11 is complementarily recorded by a plurality of scans will be described.

  FIG. 7 is a timing chart (1) in the case of performing four-pass printing (complementary printing with four scans). In FIG. 7, as in FIG. 5, LTCLK, DCLK, IDATA, BENB0-3 and HEAT in the figure are the latch clock LTCLK, data clock DCLK, image data IDATA, decoder inputs BENB0-3, The heat signal HEAT is shown.

  The 192-bit image data IDATA is temporarily taken into the shift register 61 in synchronization with the data clock DCLK. When the latch clock LTCLK is input to the shift register 61, it is transferred to the latch 62 and output to each of the 192-bit outputs of the latch 62. On the other hand, the block selection signals BENB0-3 are decoded into BE0-11 by the decoder 63, and ANDed by AND gates G1-G192 together with the output of the heat signal HEAT and the latch 62. The heaters H1 to H192 connected to the power transistors T1 to T192 to which drive signals are output from the AND gates G1 to G192 are energized, whereby ink is ejected from the liquid application nozzle 2 to the sheet 11. Recording is performed.

  In the case of pass recording, all 12 blocks are driven by one recording data transfer, whereas in the case of 4 pass recording, only 3 blocks are driven. Furthermore, in the 4-pass printing, the combinations of the three blocks that are driven in order are “0, 4, 8”, “2, 6, 10”, “3, 7, 11”, “1, 5, 9”. All the 12 blocks are driven in four times.

  The 4-pass printing is different from the 1-pass printing in that the data clock DCLK and the image data IDATA are output again in order to switch the three blocks to be driven. However, the image data IDATA of the 192-bit all-liquid coating nozzle 2 is output. The time required for transfer is sufficiently shorter than the time required for driving in three divisions. For this reason, when the inkjet recording apparatus 50 performs four-pass recording, it is possible to form an image in substantially the same time as when one-pass recording is performed.

  FIG. 8 is a dot arrangement diagram when four-pass printing is performed with the recording head 4 in accordance with the timing chart of FIG. In the figure, dots indicated by black marks are dots on which an image is recorded in one pass. Since the dot pattern recorded in one pass is a quarter of the total, one pass results in 25% random thinning recording as shown in FIG. In addition, although there are dots where the dot position is shifted from the original position in the main scanning direction, as in the case of the dot indicated by area A in FIG. There is no problem in image formation.

  As can be seen from the drive timings shown in FIGS. 5 and 7, in order to perform recording with the same number of dots as the recording performed while the recording head 4 moves by one column in one-pass recording, four in four-pass recording. It is necessary to move the column and record. For this reason, when performing 4-pass printing, the carriage 3 is moved at a speed four times that of 1-pass recording so that the recording speed does not decrease when performing 4-pass printing. That is, the time required for the carriage 3 to move the distance d shown in FIG. 6 in one-pass printing is equal to the time required for the carriage 3 to move the distance D shown in FIG. 8 in four-pass printing. As described above, the rotational speed of the main scanning motor 5 is controlled to increase the moving speed of the carriage 3.

  Normally, if the carriage 3 is moved at a speed of 4 times, the ejection frequency of each liquid application nozzle 2 is also increased 4 times. However, if one liquid application nozzle 2 is focused, it is driven only once in 4 columns. The ejection frequency for each coating nozzle 2 is the same for 4-pass printing and 1-pass printing. For this reason, the ejection performance required for each liquid application nozzle 2 is also the same for 4-pass printing and 1-pass printing.

  In the conventional four-pass recording, a recording image is thinned out in order to obtain recording data for each pass. On the other hand, in 4-pass printing by the inkjet printing apparatus 50, 192-bit image data stored in the shift register 61 is selected by 1/4 (48 bits) for each pass, and the 48-bit data is selected. Is used for time-sharing recording. For this reason, in the four-pass recording by the inkjet recording apparatus 50, the thinning process of the recorded image is not necessary. Accordingly, the inkjet recording apparatus 50 does not require a storage element such as a mask ROM for obtaining sampling data corresponding to each pass, which is necessary in the conventional multi-pass recording, and the cost of the entire recording apparatus can be reduced. It becomes.

  Further, regarding the transfer time of the recording data, since the transfer time for 192 bits is 19 μsec when the transfer clock (data clock DCLK) = 10 MHz, there is a problem even if the discharge frequency becomes 40 kHz (25 μsec), which is four times. Must not.

  Here, four-pass printing has been described as an example of multi-pass printing. However, when the number of passes is other than four, the drive pattern of the recording head 4 may be changed as shown in FIG. . FIG. 9 is a diagram illustrating the relationship between the number of passes and the drive pattern of the recording head. When performing 2-pass printing, for example, control is performed to alternately drive even blocks and odd blocks. In the case of performing 3-pass printing, for example, combinations of 4 blocks that are driven simultaneously are 3 of “0, 3, 6, 9”, “1, 4, 7, 10”, “2, 5, 8, 11”. Control is performed to switch the combination and drive in turn.

  In FIG. 9, the driving pattern for 1-pass printing is indicated by driving pattern 1-1, and even-numbered blocks and odd-numbered blocks for 2-pass printing are alternately driven, and the driving patterns are indicated by driving patterns 2-1 and 2-2, respectively. ing. In addition, combinations of blocks to be simultaneously driven in three-pass printing “0 · 3 · 6 · 9”, “1 · 4 · 7 · 10” and “2 · 5 · 8 · 11” are designated as drive patterns 3-1, Combinations of blocks indicated by 3-2 and 3-3 and simultaneously driven by 4-pass printing “0 · 4 · 8”, “2 · 6 · 10”, “3 · 7 · 11”, “1 · 5 · 9” Are indicated by drive patterns 4-1, 4-2, 4-3 and 4-4, respectively.

  Also in the case of multi-pass printing other than these four-pass printing, it is necessary to increase the moving speed of the carriage 3 in accordance with the increase in the number of passes so as not to reduce the printing speed. 10 and 11 are flowcharts showing a procedure for setting the carriage speed in accordance with the number of passes.

  The CPU 101 of the inkjet recording apparatus 50 first determines whether the number of recording passes is 4 (step S110). If the number of recording passes is not four (step S110, No), the CPU 101 determines whether or not the number of recording passes is three (step S120). When the number of recording passes is not 3 (step S120, No), the CPU 101 determines whether the number of recording passes is 2 (step S130).

  If the number of recording passes is not two (step S130, No), the CPU 101 sets the carriage speed to a normal moving speed (moving speed in one-pass printing) (step S140).

  Thereafter, the ink jet recording apparatus 50 performs one line recording, and performs paper feeding by the width (short direction) of all the liquid application nozzles 2 (steps S150 and S160). The ink jet recording apparatus 50 determines whether image recording for a predetermined line has been completed (step S170). The ink jet recording apparatus 50 repeats the processes in steps S150 to S170 until image recording for a predetermined line is completed. When the image recording for the predetermined line is completed (step S170, Yes), the inkjet recording apparatus 50 ends the image recording on the paper 11.

  If the number of recording passes is two (step S130, Yes), the CPU 101 sets the carriage speed so that the carriage speed is twice the moving speed in one-pass recording (step S180).

  Thereafter, the ink jet recording apparatus 50 performs the first pass recording with the drive pattern 2-1, and performs paper feeding by a half of the width of all the liquid application nozzles 2 (steps S190 and S200). Further, the ink jet recording apparatus 50 performs the second pass recording with the drive pattern 2-2, and performs paper feeding by a half of the width of all the liquid application nozzles 2 (steps S210 and S220). The ink jet recording apparatus 50 determines whether image recording for a predetermined line has been completed (step S230). The inkjet recording apparatus 50 repeats the processes in steps S200 to S230 until image recording for a predetermined line is completed. When the image recording for a predetermined line is completed (step S230, Yes), the inkjet recording apparatus 50 ends the image recording on the paper 11.

  When the number of recording passes is 3 (step S120, Yes), the CPU 101 sets the carriage speed so that the carriage speed is three times the moving speed in 1-pass printing (step S310).

  Thereafter, the ink jet recording apparatus 50 performs the first pass recording with the drive pattern 3-1, and performs paper feeding by 1/3 of the width of the all liquid application nozzles 2 (steps S320 and S330). Further, the ink jet recording apparatus 50 performs the second pass recording with the drive pattern 3-2 and performs paper feeding by 1/3 of the width of all the liquid application nozzles 2 (steps S340 and S350). Further, the ink jet recording apparatus 50 performs the third pass recording with the drive pattern 3-3, and performs paper feeding by 1/3 of the width of all the liquid application nozzles 2 (steps S360 and S370). The ink jet recording apparatus 50 determines whether image recording for a predetermined line has been completed (step S380). The ink jet recording apparatus 50 repeats the processes of steps S320 to S380 until image recording for a predetermined line is completed. When the image recording for the predetermined line is completed (step S380, Yes), the inkjet recording apparatus 50 ends the image recording on the paper 11.

  When the number of recording passes is 4 (step S110, Yes), the CPU 101 sets the carriage speed so that the carriage speed is four times the moving speed in 1-pass printing (step S390).

  Thereafter, the ink jet recording apparatus 50 performs the first pass recording with the drive pattern 4-1, and performs paper feeding by ¼ of the width of all the liquid application nozzles 2 (steps S400 and S410). Further, the ink jet recording apparatus 50 performs the second pass recording with the drive pattern 4-2, and performs paper feeding by ¼ of the width of all the liquid application nozzles 2 (steps S420 and S430). Further, the ink jet recording apparatus 50 performs the third pass recording with the drive pattern 4-3, and performs paper feeding by ¼ of the width of all the liquid application nozzles 2 (steps S440 and S450). Further, the ink jet recording apparatus 50 performs the fourth pass recording with the drive pattern 4-4, and performs paper feeding by ¼ of the width of all the liquid application nozzles 2 (steps S460 and S470). The inkjet recording apparatus 50 determines whether image recording for a predetermined line has been completed (step S480). The ink jet recording apparatus 50 repeats the processes in steps S400 to S480 until image recording for a predetermined line is completed. When the image recording for a predetermined line is completed (step S480, Yes), the inkjet recording apparatus 50 ends the image recording on the paper 11. As described above, the ink jet recording apparatus 50 increases the moving speed of the carriage 3 in accordance with the number of passes so that the recording speed does not decrease even if the number of passes increases.

  Next, the recording state of the nozzle row 20 when 4-pass printing is performed by the driving method shown in FIG. 8 will be described with reference to FIG. FIG. 12 shows which drive pattern is selected for the same area on the recorded image. Drive patterns 4-1 to 4-4 show the drive patterns 4-1 to 4-4 shown in FIG. 9, respectively. Each square corresponds to a region (12 dots) surrounded by a dotted line in FIG. 8, and each of P1 to P4 corresponding to the first to fourth passes indicates a region of 5 columns × 4 groups.

  In the first pass, the 48 liquid application nozzles 2 on the lower side of the nozzle row 20 record images, and after the paper 11 moves relatively by the 48 liquid application nozzles 2, the second pass To be recorded. For this reason, the liquid application nozzles 2 used when recording the same area are shifted upward by 48 each time one pass is completed. The ink jet recording apparatus 50 divides and records 192 liquid application nozzles in four passes of 48, so that the recording of all dots is completed in four passes without shifting the drive pattern for each pass.

  When the number of liquid coating nozzles 2 and the shift amount of the liquid coating nozzles 2 for each pass are different, it is necessary to adjust the cycle of the driving pattern by a predetermined column for each pass.

  Next, a recording state when an image is recorded with a color recording head will be described. FIG. 13 is a diagram showing drive patterns at each carriage position for one main scan. One square corresponds to 12 dots as in FIG. P1 is an initial position of the carriage 3, and P2 is a carriage position moved from the carriage position of P1 by the interval (short direction) of the nozzle rows 20 in the main scanning direction. In other words, in P2, the image is superimposed and recorded by the nozzle row 20 on the left side of the nozzle row 20 in P1 at the position where each nozzle row 20 has recorded an image in P1. In P3 and P4, the carriage 3 further moves and the nozzle row 20 overlaps to record an image.

  In the area surrounded by the bold line, after the Bk ink is ejected in P1, the nozzle rows 20 of the respective colors C, M, and Y record images in the same area in P2 to P4. For this reason, the area in which the image image is recorded by the nozzle row 20 has different timings for all of the four nozzle rows 20. Therefore, an image is not recorded on the same dot in a short time. As a result, it is possible to minimize dot deviation due to bleeding between inks or ink drawing. Here, the color recording head having a plurality of nozzle rows 20 has been described, but the same effect can be obtained even in the case of the recording head 4 having a plurality of nozzle rows 20 of the same color.

  Incidentally, in the recording head 4, as shown in FIG. 14, among the signals shown in the timing charts of FIGS. 5 and 7, all of the signals other than the image data IDATA and the heat signal HEAT that defines the time for driving the heater are included. The signal is a signal common to the four logic circuits. For this reason, the block to be driven for each nozzle row 20 of each color (Y, M, C, Bk) cannot be changed. Therefore, the ink jet recording apparatus 50 realizes a recording state as shown in FIG. 13 by changing the distance (arrangement interval) between the nozzle rows 20. For example, FIG. 13 shows a recording state when the distance between the nozzle arrays 20 is (4m + 1) times (m is a natural number) the main scanning resolution pitch.

  Here, the case where the distances between the nozzle rows 20 are the same has been described, but the distances between the nozzle rows 20 need not be the same as long as the condition that the distance between the nozzle rows 20 is (4m + 1) times the main scanning resolution pitch is satisfied. . As shown in FIG. 15, in the recording head 4 configured to supply all signals independently for each nozzle row 20, the distance between the nozzle rows 20 can be arbitrarily set.

  Although the case where the logic circuit 60 having the configuration shown in FIG. 4 is driven by the timing charts shown in FIGS. 5 and 7 has been described as an example here, the configuration of the logic circuit may be the configuration shown in FIG.

  FIG. 16 is a block diagram (1) showing another configuration of the logic circuit. The logic circuit 70 shown in FIG. 16 transfers the data of 16 liquid application nozzles 2 driven by the drive block. In this case, the logic circuit 70 may be driven according to the timing charts shown in FIGS. FIG. 17 is a timing chart (2) when the logic circuit 70 performs 1-pass printing, and FIG. 18 is a timing chart (2) when the logic circuit 70 performs 4-pass printing. Thus, even when the logic circuit 70 is used for driving the recording head 4, the same effect as when the logic circuit 60 is used for driving the recording head 4 can be obtained.

  Further, the configuration of the logic circuit may be different from the logic circuit 60 shown in FIG. 4 or the logic circuit 70 shown in FIG. FIG. 19 is a block diagram (2) showing another configuration of the logic circuit. The logic circuit 80 shown in FIG. 19 does not input BENB0 to 3 signals from the outside, and transfers the data of 16 liquid application nozzles 2 and the data of the drive block number to the recording head 4 together for each block. To do. In this case, the logic circuit 80 may be driven according to the timing charts shown in FIGS. FIG. 20 is a timing chart (3) when the logic circuit 80 performs 1-pass printing, and FIG. 21 is a timing chart (3) when the logic circuit 80 performs 4-pass printing. Thereby, even when the logic circuit 80 is used to drive the recording head 4, the same effect as when the logic circuits 60 and 70 are used to drive the recording head 4 can be obtained.

  In this way, the plurality of liquid application nozzles 2 are divided into a plurality of blocks, the liquid application nozzle block to be driven simultaneously is selected, and the carriage speed is increased in accordance with the number of passes in multi-pass recording. High speed can be maintained.

  In addition, since the number of liquid coating nozzles 2 driven at a time does not increase by multipass printing and time-division driving, the power required to drive the liquid coating nozzles 2 can be kept low. As a result, an increase in cost and weight due to an increase in the capacity of the printer power supply can be avoided.

  Further, since the image recorded on the paper 11 is automatically skipped by the multi-pass recording control and the time-division driving control, an element such as a mask ROM for obtaining sampling data corresponding to each pass Is unnecessary, and the inkjet recording apparatus 50 can be manufactured at low cost.

  Further, since the ink jet recording apparatus 50 does not print ink on the same dot in a short time, it can minimize dot deviation due to bleeding or ink drawing between a plurality of inks. It is possible to record a color image.

  Here, the case where the plurality of nozzle arrays 20 are integrated into one recording head 4 has been described. However, in a printer equipped with a plurality of recording heads 4 as well, due to bleeding between the plurality of inks and ink drawing. Dot shift can be suppressed. When the printer has a plurality of recording heads 4, the image data to be recorded is supplied to each recording head 4 individually. Therefore, as with the inkjet recording apparatus 50, in addition to the method of adjusting the distance between the nozzle rows 20, the cycle of the drive pattern is shifted for each recording head 4 to adjust the cycle of the drive pattern for each pass. You can also.

  Further, here, the recording head 4 that drives the liquid coating nozzles 2 adjacent to each other in different blocks has been described, but there are eight liquid coating nozzles 2 arranged continuously from the upper side as shown in FIG. The recording head 4 of the ink jet recording apparatus 50 may be applied to a recording head of eight types that are driven simultaneously. FIG. 22 shows a dot arrangement diagram in a case where eight liquid application nozzles arranged continuously from the upper side are driven simultaneously by eight to record an image.

  Further, the case has been described in which the liquid droplets ejected from the recording head 4 are ink and the liquid stored in the ink tank is ink, but the contents stored in the ink tank are not limited to ink. For example, in order to improve the fixability and water resistance of the recorded image or to improve the image quality, a processing liquid or the like discharged onto the paper 11 may be stored in the ink tank. Moreover, although the case where the heaters H1 to H192 are used as the recording elements has been described, the present invention is not limited to this, and a piezo element may be used as the recording elements.

  As described above, when it is confirmed that the carriage 3 has moved to a predetermined printing position, the ink jet recording apparatus 50 transfers data to be printed to the recording head 4 (head module) and prints on the paper 11. This print data (image data IDATA) is transferred by, for example, serial transfer in order to efficiently perform the transfer with the minimum number of data lines. Serial transfer is performed by a data transfer clock and print data.

  FIG. 23 is a diagram for explaining noise characteristics of radiation noise. The noise characteristics shown on the left side of FIG. 23 indicate a case where signal lines that perform simultaneous switching concentrate in a narrow frequency band. When switching is performed in a narrow frequency band, high noise is generated. Further, the noise characteristic shown on the right side of FIG. 22 shows a case where a wide frequency band is provided and switching is performed in this band. When switching is performed in a wide frequency band, noise is dispersed. As described above, when switching is performed in a wide frequency band, radiation noise due to frequency spreading is reduced as compared with switching in a narrow frequency band. In the present embodiment, radiation noise is reduced by switching in a wide frequency band.

  Next, the transfer reference clock (data transfer reference clock) and the print data timing when data is transferred to the logic circuit 60 of the recording head 4 will be described. The transfer reference clock is a clock serving as a reference for the print data transfer timing. FIG. 24 is a diagram showing a transfer reference clock and print data transfer timing that are conventionally used. FIG. 24 shows a case where the transfer reference clock and print data are transferred to the logic circuit 60 using a transfer method that does not take noise countermeasures. The transfer reference clock (CLK) is always clocked out with a cycle of the period tp. Further, the print data (Data_1, Data_2) is output with a predetermined delay time with respect to the transfer reference clock by the setup (tS) and hold (tH) satisfying the AC characteristics of the logic circuit 60.

  FIG. 25 is a diagram showing a transfer reference clock and print data transfer timing used in the ink jet recording apparatus according to the embodiment of the present invention. The transfer reference clock (CLK) here corresponds to the data clock DCLK shown in FIG. 4 and the like, and the first print data (Data_1) and the second print data (Data_2) here are shown in FIG. Corresponds to the image data IDATA shown in FIG. Further, tODLY1, tODLY2, setups tS1, tS2, and holds tH1, tH2 correspond to the print information described in the claims.

  The ink jet recording apparatus 50 outputs a transfer reference clock (CLK) (clock information) alternately with a cycle tP1 and a cycle tP2. In other words, the inkjet recording apparatus 50 switches and outputs a plurality of types of cycles in order so that the cycle of the transfer reference clock is not constant.

  The inkjet recording apparatus 50 outputs the first print data (Data_1) with a first delay time (tODLY1) with respect to the transfer reference clock, and outputs the second print data (Data_2) with respect to the transfer reference clock. Output with the second delay time (tODLY2). In other words, the inkjet recording apparatus 50 outputs print data with a different delay time for each head module. Then, the cycle switching timing of the transfer reference clock is changed every time print data is switched (every data switching timing). Specifically, the case where the cycle is changed from the cycle tP2 to the cycle tP1 when the data D1 is switched to the data D2, and the cycle is changed from the cycle tP1 to the cycle tP2 when the data D2 is switched to the data D3 is shown.

  The setting method of the periods tP1, tP2, delay times tODLY1, tODLY2, and the like are set as software as output timing information in an ASIC in the engine control unit (head module control unit) 100. Various settings are made to the ASIC by external input from a predetermined input means (not shown). The logic circuit 60 operates based on the output timing information set in the ASIC. The ASIC is a part of the engine control unit 100 excluding the CPU 101 and the host I / F unit 102.

  The cycle switching timing of the transfer reference clock is not limited to changing every data switching as shown in FIG. 25, but may be changed based on the printing position of information on the recording medium. FIG. 26 is a diagram for describing the cycle of the transfer reference clock when the cycle switching timing of the transfer reference clock changes based on the print position. FIG. 26 shows a case where print data transfer is started in synchronization with the reading position (carriage position) of the encoder sheet.

  Positions X1 to X3 shown in FIG. 26 are printing start positions. The period of the transfer reference clock corresponding to the position X1 and the position X3 is the period tP1, and the transfer reference clock period of the position X2 is the period tP2. In other words, every time the print start position changes, the transfer reference clock cycle is alternately changed between the cycle tP1 and the cycle tP2.

  FIG. 26 shows a case where the period tP1 is changed to the period tP2 when the position X1 is switched to the position X2, and the period tP2 is changed to the period tP1 when the position X2 is changed to the position X3. Switching between the period tP1 and the period tP2 is performed by setting ASIC settings to tP1 = n (n is a natural number) 1 and tP2 = m (m is a natural number). Here, n is the number of times the print start position is switched before switching from the cycle tP1 to the cycle tP2. Here, m is the number of times the print start position is switched before switching from the period tP2 to the period tP1. Therefore, when the cycle tP1 and the cycle tP2 are switched as shown in FIG. 26 (when the cycle is switched every time the print start position changes once), the ASIC settings are set to tP1 = 1 and tP2 = 1.

  Further, for example, when the print start position is switched three times, the cycle tP1 is switched to the cycle tP2, and when the print start position is switched twice, the cycle tP2 is switched to the cycle tP1, tP1 = 3. Set tP2 = 2. Accordingly, for example, when tP1 = 3 and tP2 = 2 are set, the transfer reference clock period in the period between the positions X1 to X3 becomes the period tP1, and the transfer reference clock period in the period between the positions X4 and X5 (not shown) is the period tP2. It becomes.

  As described above, since the ink jet recording apparatus 50 can variably set a state with a high EMI effect by software setting, it is possible to reduce noise without increasing the cost of additional components or the like.

  In the present embodiment, the set number of cycles (tP1, tP2, tP3,...) And the set number of delay times (tODLY1, tODLY2, tODLY3,...) Are set according to the number of liquid application nozzles 2 and the like. It can be set as desired.

  Note that the cycle and the delay time of the transfer reference clock are not limited to being set separately one by one, but the cycle may be changed within a predetermined range. For example, the period may be set like a pseudo SSCG by setting the period to, for example, a fluctuation range (variation range) of −3% within the frequency variable band of the transfer reference clock. As a pseudo SSCG method (frequency fluctuation method), when the fluctuation range is set to −3%, the transfer reference clock from the ASIC to the recording head 4 (logic circuit 60) is always variable within a range of −3% fluctuation range. Is output.

  FIG. 27 is a diagram showing the timing of the transfer reference clock and print data when the cycle of the transfer reference clock is changed within a predetermined fluctuation range within the frequency variable band. In FIG. 27, the period tP1, the period tP2, the period tP3, the period tP4,... Are variably output within a range of −3% of the frequency variable band. The periodic variation rate used at this time is separately set as a variation slope value (variation rate) in the ASIC. When changing the cycle of the transfer reference clock within the frequency variable band, the cycle switching timing may be changed every clock or every printing position.

  Further, setup and hold times may be secured by controlling the hardware (the recording head drive control unit 111 in FIG. 3) so that the relationship between the cycle of the transfer reference clock and the delay time satisfies the AC characteristics of the logic circuit 60. For example, setup and hold are set in the ASIC as the relationship between the transfer reference clock and the data output. The relationship between the transfer reference clock and the delay time (tODLY) by the period setting or frequency fluctuation setting (setting of the fluctuation width within the frequency variable band) is determined by the setup of the recording head drive control unit (correction control mechanism) 111. If it is determined that the hold and hold regulations are not satisfied, the delay time value that does not satisfy the setup and hold is ignored. The recording head drive control unit 111 performs control to guarantee the operation of the head module by giving priority to the AC characteristics of the logic circuit 60.

  Note that when there is a relationship represented by the following expression (1), setup of data (Data_1) cannot be ensured as shown in the period (tp1 to tp2) of FIG. For this reason, the section of tS1 where tS1 satisfies the expression (1) is the AC characteristic unachieved section (the section in which the AC characteristic of the logic circuit 60 is prioritized).

  Minimum period tp1-tODLY1 ≧ tS1 (1)

  Until the period of tS1 can be secured, the delay time satisfying the following expression (2) is set as the actual data output delay time.

  Minimum period tp1-tODLY1 <tS1 (2)

  In the present embodiment, the case where image formation is performed by the ink jet recording apparatus 50 has been described. However, image formation may be performed by an image forming composite apparatus (multifunction machine) such as a FAX having an ink jet function.

  FIG. 28 is a block diagram showing the hardware configuration of the multifunction machine 201. As shown in the figure, the multifunction machine 201 has a configuration in which a controller 210 and an engine unit (Engine) 260 are connected by a PCI (Peripheral Component Interconnect) bus. The controller 210 is a controller that controls the entire MFP 201 and controls drawing, communication, and input from the operation unit (input unit) 220. The engine unit 260 is a printer engine that can be connected to a PCI bus, and is, for example, a monochrome plotter, a 1-drum color plotter, a 4-drum color plotter, a scanner, or a fax unit. The engine unit 260 includes an image processing unit such as error diffusion and gamma conversion in addition to a so-called engine unit such as a plotter.

  The controller 210 includes a CPU 211, a north bridge (NB) 213, a system memory (MEM-P) 212, a south bridge (SB) 214, a local memory (MEM-C) 217, and an ASIC (Application Specific Integrated Circuit). 216 and a hard disk drive (HDD) 218, and the north bridge (NB) 213 and the ASIC 216 are connected by an AGP (Accelerated Graphics Port) bus 215. The MEM-P 212 further includes a ROM (Read Only Memory) 212a and a RAM (Random Access Memory) 212b.

  The CPU 211 performs overall control of the multifunction machine 201, has a chip set including the NB 213, the MEM-P 212, and the SB 214, and is connected to other devices via this chip set.

  The NB 213 is a bridge for connecting the CPU 211 to the MEM-P 212, SB 214, and AGP 215, and includes a memory controller that controls reading and writing to the MEM-P 212, a PCI master, and an AGP target.

  The MEM-P 212 is a system memory used as a memory for storing programs and data, a memory for developing programs and data, a printer drawing memory, and the like, and includes a ROM 212a and a RAM 212b. The ROM 212a is a read-only memory used as a memory for storing programs and data, and the RAM 212b is a writable and readable memory used as a program / data development memory, a printer drawing memory, and the like.

  The SB 214 is a bridge for connecting the NB 213 to a PCI device and peripheral devices. The SB 214 is connected to the NB 213 via a PCI bus, and a network interface (I / F) unit and the like are also connected to the PCI bus.

  The ASIC 216 is an IC (Integrated Circuit) for image processing application having hardware elements for image processing, and has a role of a bridge for connecting the AGP 215, the PCI bus, the HDD 218, and the MEM-C 217. The ASIC 216 includes a PCI target and an AGP master, an arbiter (ARB) that forms the core of the ASIC 216, a memory controller that controls the MEM-C 217, and a plurality of DMACs (Direct Memory) that rotate image data using hardware logic. Access Controller) and a PCI unit that performs data transfer between the engine unit 260 via the PCI bus. The ASIC 216 is connected to an FCU (Fax Control Unit) 230, a USB (Universal Serial Bus) 240, and an IEEE 1394 (the Institute of Electrical and Electronics Engineers 1394) interface 250 via a PCI bus.

  The MEM-C 217 is a local memory used as a copy image buffer and a code buffer, and an HDD (Hard Disk Drive) 218 is a storage for storing image data, programs, font data, and forms. It is.

  The AGP 215 is a bus interface for a graphics accelerator card that has been proposed to speed up graphics processing. The AGP 215 speeds up the graphics accelerator card by directly accessing the MEM-P 212 with high throughput. .

  Note that the image forming program executed by the inkjet recording apparatus 50 and the multifunction peripheral 201 of the present embodiment is provided by being incorporated in advance in a ROM or the like. The image forming program executed by the inkjet recording apparatus 50 or the multifunction machine 201 according to the present embodiment is a CD-ROM, flexible disk (FD), CD-R, DVD (installable format or executable format file). It may be configured to be recorded and provided on a computer-readable recording medium such as Digital Versatile Disk).

  Further, the image forming program executed by the ink jet recording apparatus 50 or the multifunction machine 201 according to the present embodiment is stored on a computer connected to a network such as the Internet and is provided by being downloaded via the network. May be. Further, the image forming program executed by the inkjet recording apparatus 50 or the multifunction machine 201 of the present embodiment may be provided or distributed via a network such as the Internet.

  The image forming program executed by the inkjet recording apparatus 50 and the multifunction machine 201 according to the present embodiment has a module configuration including each part of the engine control unit 100 described above, and a CPU (processor) is used as actual hardware. When the image forming program is read from the ROM and executed, the respective units are loaded onto the main storage device, and the respective units of the engine control unit 100 are generated on the main storage device.

  Thereby, since the cycle of the transfer reference clock is changed by software setting, it is possible to improve the EMI countermeasure effect with a simple configuration. In addition, since the cycle of the transfer reference clock is changed by software setting, it is possible to easily set according to the liquid application nozzle.

  Thus, according to the embodiment, the print data switching timing can be variably set with respect to the transfer reference clock (print data output reference clock), so that the transfer reference clock can be spread in frequency. As a result, unnecessary noise due to the transfer reference clock and the data signal can be reduced, and the EMI countermeasure effect can be improved with a simple configuration. Therefore, it is possible to reduce noise without increasing the cost of additional parts or the like.

  In addition, since various transfer reference clock cycle switching timings can be set, the change timing can be set by checking the most effective switching timing as an EMI countermeasure in the actual machine. This makes it possible to take EMI countermeasures without relying on additional components. In the development stage of the inkjet recording apparatus 50 and the like, it is essential to determine an accurate switching period of the cycle based on the result of actual machine evaluation. In the present embodiment, it is possible to easily realize noise countermeasures during actual machine evaluation by setting the AC characteristics of the head module to ASIC (software setting).

  In addition, since the print data switching timing and the frequency spread of the transfer reference clock can be constantly changed by the fluctuation slope value of the periodic fluctuation rate within the frequency variable band, the pseudo SSCG (spread spectrum spread) can be easily set by a simple software setting. ) It is possible to obtain an effect.

  Further, since the recording head 4 operates the ink jet recording apparatus 50 so that the recording head drive control unit 111 satisfies the AC characteristics of the print data and the transfer reference clock, the pseudo SSCG effect can be easily obtained by simple software setting. It becomes possible.

1 is a plan view showing a schematic configuration of an ink jet recording apparatus according to an embodiment. 1 is a front view illustrating a schematic configuration of an ink jet recording apparatus according to an embodiment. It is a functional block diagram which shows the structure of an engine control part. FIG. 3 is a block diagram illustrating a configuration of a logic circuit of a recording head. FIG. 10 is a timing chart (1) in a case where one-pass printing is performed by time-division driving the nozzle row for each block by a logic circuit. FIG. 5 is a dot arrangement diagram when an image is recorded by driving a nozzle row in a time-sharing manner for each block. It is a timing chart (1) in the case of performing 4-pass printing. FIG. 8 is a dot arrangement diagram when four-pass printing is performed with the recording head 4 in accordance with the timing chart of FIG. 7. FIG. 6 is a diagram illustrating a relationship between the number of passes and a drive pattern of a recording head. It is a flowchart (1) which shows the setting procedure of the carriage speed according to the number of passes. It is a flowchart (2) which shows the setting procedure of the carriage speed according to the number of passes. It is a figure which shows which drive pattern is selected with respect to the same area on a recorded image. It is a figure which shows the drive pattern in each carriage position with respect to one main scanning. It is a figure for demonstrating the signal common to four logic circuits. FIG. 4 is a diagram for explaining a recording head configured such that all signals are supplied independently for each nozzle row. It is a block diagram (1) which shows the other structure of a logic circuit. FIG. 17 is a timing chart (2) when the logic circuit of FIG. 16 performs one-pass printing. It is a timing chart (2) in case the logic circuit of FIG. 16 performs 4-pass printing. It is a block diagram (2) which shows the other structure of a logic circuit. FIG. 19 is a timing chart (3) when the logic circuit of FIG. 18 performs one-pass printing. FIG. FIG. 19 is a timing chart (3) when the logic circuit of FIG. 18 performs 4-pass printing. FIG. FIG. 8 is a dot arrangement diagram in a case where eight liquid application nozzles arranged continuously from the upper side are driven simultaneously by eight to record an image. It is a figure for demonstrating the noise characteristic of radiation noise. It is a figure which shows the transfer reference clock and the transfer timing of print data which were used conventionally. It is a figure which shows the transfer reference clock used with the inkjet recording device which concerns on embodiment, and the transfer timing of print data. It is a figure for demonstrating the period of a transfer reference clock when the period switching timing of a transfer reference clock changes based on a printing position. It is a figure which shows the timing of a transfer reference clock and print data at the time of changing the period of a transfer reference clock within the range of the predetermined fluctuation range within a frequency variable band. FIG. 2 is a block diagram illustrating a hardware configuration of a multifunction machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Guide lot 2 Liquid application nozzle 3 Carriage 4y, 4c, 4m, 4k Recording head 5 Main scanning motor 6 Driving pulley 7 Driven pulley 8 Timing belt 10 Encoder scale 11 Paper 12 Conveying belt 13 Conveying roller 14 Tension roller 15 Charging roller 18 Encoder 20 Nozzle array 50 Inkjet recording device 60, 70, 80 Logic circuit 61 Shift register 62 Latch 63 Decoder 100 Engine control unit 101 CPU
DESCRIPTION OF SYMBOLS 102 Host I / F part 103 Image processing part 104 Image data storage part 105 Recording head drive waveform storage part 106 Main scanning motor drive part 107 Edge detection part 108 Main scanning speed detection part 109 Main scanning position detection part 110 Print area determination part 111 Recording head drive control unit 200 Host 201 Multifunction machine 210 Controller 211 CPU
212 MEM-P
213 NB
214 SB
215 AGP bus 216 ASIC
217 MEM-C
218 HDD
220 Operation unit 230 FCU
240 USB
250 IEEE1394 interface 260 Engine part G1 to G192 AND gate H1 to H192 Heater T1 to T192 Power transistor

Claims (10)

When printing information on a recording medium, print data used for printing the information and an output reference clock serving as a reference for outputting the print data are input to the head module, and the head module outputs the print data and the output reference. In the image forming apparatus for printing the information on the recording medium based on a clock,
A head module controller that inputs print information relating to the output timing of the print data and clock information relating to the output reference clock to the head module as output timing information;
The image forming apparatus according to claim 1, wherein the output timing information is information for outputting the print data by sequentially switching a plurality of types of cycles so that the cycle of the output reference clock is not constant.   The image forming apparatus according to claim 1, further comprising an input unit that externally inputs the print information and the clock information and sets the output timing information in the head module control unit.   The image forming apparatus according to claim 1, wherein the print information has a delay time from the output of the output reference clock to the output of the print data.   The image forming apparatus according to claim 1, wherein the head module control unit inputs output timing information having a different delay time for each head module to each of the head modules. .   The image forming apparatus according to claim 1, wherein the cycle of the output reference clock is set to be switched every time the print data is switched.   The image forming apparatus according to claim 1, wherein the cycle of the output reference clock is set so as to be switched based on a printing position of information on the recording medium.   The head module control unit sets the plurality of types of cycles based on a preset variation range and rate of the output reference clock cycle, and outputs the output timing information using the set types of cycles. The image forming apparatus according to claim 1, wherein the image is input to the head module.   The image forming apparatus according to claim 1, wherein the head module control unit controls an output timing of the print data so as to satisfy an AC characteristic of the head module. When printing information on a recording medium, print data used for printing the information and an output reference clock serving as a reference for outputting the print data are input to the head module, and the head module outputs the print data and the output reference. In an image forming method for printing the information on the recording medium based on a clock,
A head module control step of inputting information relating to the output timing of the print data and information relating to the output reference clock to the head module as output timing information,
The image forming method according to claim 1, wherein the output timing information is information for outputting the print data by sequentially switching a plurality of types of cycles so that the cycle of the output reference clock is not constant. An image forming program which causes a computer to execute the image forming method according to claim 9.

Images